So, is your g-box working now? If not, it's pretty easy to check most of those components with a multimeter if you have one, I could probably help you with that. I'd guess one of the black diodes or the voltage regulator as the culprit, or a stuck/welded relay contact as I think it was Waylew suggested. Using a magnifying glass, or jeweler's loupe, if you have one, is good for looking for burnt components, sometimes when they burn it's only a tiny hole or crack in the case of the component and real hard to see. Traces on the bottom of the board could have burned off also. A shorted diode [or two] , or voltage regulator would probably also be a lot hotter than the rest while the unit is powered on and you could feel if any are hotter than the rest. Be careful though, they definitely can be hot enough to burn and also you don't want to touch any leads and use only one hand when probing around inside, stuff your other hand into your pocket, you don't want to get shocked. It doesn't look like anything in there could shock you very bad but I've never worked on a g-box before, so I don't know.